Data from: It’s not all black and white: investigating colour polymorphism in manta rays across Indo-Pacific populations

Intraspecific colour polymorphisms have been the focus of numerous studies, yet processes affecting melanism in the marine environment remain poorly understood. Arguably the most prominent example of melanism in marine species occurs in manta rays (Mobula birostris and M. alfredi). Here, we use photo identification catalogues to document the frequency variation of melanism across Indo-Pacific manta ray populations and test for evidence of selection by predation acting on colour morph variants. We use mark-recapture modeling to compare colour morph survivorship in three M. alfredi populations and assess the relationship between frequency variation and geographical distance. While large differences in melanism frequencies existed among populations of both species (0-40%), apparent survival estimates revealed no difference in survivorship between morphs. We found a significant association between phenotypic and geographical distance in M. birostris, but not in M. alfredi. Our results suggest melanism is not under selection by predation in the tested M. alfredi populations, and that frequency differences across populations of both species are a consequence of neutral genetic processes. As colour polymorphisms are often subjected to complex selection mechanisms, our findings only begin to elucidate the underlying evolutionary processes responsible for the maintenance and frequency variation of melanism in manta ray populations.

Usage Notes
Mark.KomodoNPcsv file with .inp formatted sightings data for Program MARK - Komodo, IndonesiaMark.NusaPenidacsv file with .inp formatted sightings data for Program MARK - Nusa Penida, IndonesiaMark.RajaAmpatcsv file with .inp formatted sightings data for Program MARK - Raja Ampat, West Papua, IndonesiaMark.Mozambiquecsv file with .inp formatted sightings data for Program MARK - Praia do Tofo, MozambiqueventralcolourationQuantification of ventral pigmentation data - M. alfredi and M. birostris

物种间色素变异一直是众多研究的焦点，然而影响海洋环境中黑色素形成的机制仍理解不足。在海洋物种中，乌贼（Mobula birostris 和 M. alfredi）的黑素化现象或许是最为显著的例子。在本研究中，我们利用照片识别目录来记录印度-太平洋乌贼种群中黑素化频率的变化，并检验针对颜色形态变异的捕食选择作用的证据。通过标记-重捕模型，我们比较了三种 M. alfredi 种群中颜色形态的存活率，并评估了频率变化与地理距离之间的关系。尽管两种物种的种群间黑素化频率存在显著差异（0-40%），但明显的存活估计显示出不同形态之间的存活率并无差异。我们在 M. birostris 中发现了表型与地理距离之间的显著关联，但在 M. alfredi 中并未发现。我们的结果表明，在所测试的 M. alfredi 种群中，黑素化并未受到捕食选择的压力，并且两种物种种群间的频率差异是中性遗传过程的结果。鉴于颜色多态性通常受到复杂的自然选择机制的影响，我们的发现仅初步阐明了维持和频率变化所涉及的乌贼种群中黑素化的进化过程。

使用说明

Mark.KomodoNP.csv 文件，包含用于 Program MARK 的 .inp 格式的 sightings 数据 - 科莫多，印度尼西亚
Mark.NusaPenida.csv 文件，包含用于 Program MARK 的 .inp 格式的 sightings 数据 - 欧萨·佩尼达，印度尼西亚
Mark.RajaAmpat.csv 文件，包含用于 Program MARK 的 .inp 格式的 sightings 数据 - 瑞亚·安帕特，西巴布亚，印度尼西亚
Mark.Mozambique.csv 文件，包含用于 Program MARK 的 .inp 格式的 sightings 数据 - 莫桑比克普拉亚多托佛
ventralcolouration 对 M. alfredi 和 M. birostris 腹部色素化数据的量化